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Abstract:

A surgical instrument assembly configurable for performing a dermatotomy
in a percutaneous procedure and further configurable for performing cuts
in open surgery includes a pointed scalpel blade and a hollow sheath body
disposed to encapsulate the pointed scalpel blade inside a longitudinal
instrument cavity to protect a user. The hollow sheath body is supported
for longitudinal translation with respect to the scalpel blade. The
hollow sheath may be positioned and locked at a first position to
completely encapsulate the scalpel blade inside the instrument cavity for
safe handling. The hollow sheath body is movable to second and third
positions with different lengths of the surgical instrument extending out
through a front face of the hollow sheath body. A compression spring
biases the hollow sheath body toward the first safety position.

Claims:

1. A surgical instrument having a longitudinal axis, a front end and a
back end comprising: an instrument holder extending along the
longitudinal axis having an instrument holding portion disposed at the
front end, a back shaft portion disposed at the back end, and a front
shaft portion extending between the instrument holding portion and the
back shaft portion; a scalpel blade fixedly attached to the instrument
holding portion; a hollow sheath body comprising an annular wall
surrounding a second longitudinal cavity for encapsulating the scalpel
blade therein and for interfacing with the front shaft portion to movably
support the hollow sheath body for longitudinal translation with respect
to the front shaft portion and the scalpel blade; and, a handle actuator
comprising an annular wall surrounding a first longitudinal cavity for
movably receiving the hollow sheath body therein and for interfacing with
the back shaft portion to support the handle actuator with respect to the
back shaft portion and the hollow sheath body.

2. The surgical instrument of claim 1 wherein said front end comprises a
guide wire receiving groove for receiving a wire therein, said end of
said groove being positioned approximately 0.5 mm away from an aperture
on said front end of said surgical instrument to form a bridge.

3. The surgical instrument of claim 1 further comprising a compression
spring disposed on the front shaft portion between the hollow sheath body
and the back shaft portion for generating a biasing force that biases the
hollow sheath body toward the instrument front end.

4. The surgical instrument of claim 3 wherein the hollow sheath body is
movable between a first longitudinal position that encapsulates the
scalpel blade inside the second longitudinal cavity and a second
longitudinal position that causes a first desired length of the scalpel
blade to be exposed at the front end.

5. The surgical instrument of claim 4 wherein the first desired length is
suitable for performing free hand surgery.

6. The surgical instrument assembly of claim 5 wherein the first desired
length is in the range of 1.25-7.0 mm.

7. The surgical instrument of claim 4 further comprising elements
disposed between the hollow sheath body and the handle actuator for
locking the hollow sheath body in the first longitudinal position.

8. The surgical instrument of claim 7 further comprising elements
disposed between the hollow sheath body and handle actuator for locking
the hollow sheath body in the second longitudinal position.

9. The surgical instrument of claim 4 further comprising a notch passing
through the hollow sheath body for providing external access to the
scalpel blade when the hollow sheath body is in the first longitudinal
position.

10. The surgical instrument of claim 4 further comprising a front wall
for closing the second longitudinal cavity at the front end, and an
instrument aperture extending through the front wall for receiving the
scalpel blade there-through.

11. The surgical instrument of claim 4 wherein the hollow sheath body is
movable between the first longitudinal position and a third longitudinal
position that causes a second desired length of the scalpel blade to be
exposed at the front end.

12. The surgical instrument of claim 11 wherein the second desired length
is suitable for making a dermatotomy in a percutaneous procedure.

13. The surgical instrument of claim 12 wherein the second desired length
is in the range of 0.25-1.25 mm.

14. The surgical instrument of 11 further comprising a guide wire
receiving groove formed on an external surface of the hollow sheath body
at the front end for receiving a wire therein, and wherein the guide wire
receiving groove is positioned to guide the scalpel blade to make the
dermatotomy substantially coincident with a puncture surrounding the
guide wire.

15. The surgical instrument of claim 11 further comprising a guide wire
receiving groove formed on an external surface of the hollow sheath body
at the front end for receiving a wire therein, and wherein said end of
said receiving groove is positioned approximately 0.5 mm away from an
instrument aperture to form a bridge.

16. The surgical instrument of claim 11 further comprising a front wall
for closing the second longitudinal cavity at the front end and an
instrument aperture extending through the front wall for receiving the
scalpel blade there-through.

17. The surgical instrument of claim 11 further comprising a notch
passing through the hollow sheath body for providing external access to
the scalpel blade when the hollow sheath body is in the first
longitudinal position.

18. The surgical instrument of claim 16: wherein the handle actuator is
rotatably attached to the back shaft portion for rotation about the
longitudinal axis with respect to the back shaft portion and the hollow
sheath body, and further wherein the handle actuator includes a male
engaging element disposed substantially normal to the annular wall and
protruding into the first longitudinal cavity; wherein the hollow sheath
body includes a female engaging element comprising a slot arrangement
formed on the annular wall thereof to engage with the male engaging
element such that the hollow sheath body is movable to one of the first,
the second and the third longitudinal positions; and, wherein the handle
actuator is rotatable to lock the hollow sheath body at one of the first
and the second longitudinal positions.

19. The surgical instrument of claim 18 wherein the slot arrangement is
further formed with slot elements configured to allow movement of the
hollow sheath body from the first longitudinal position to the third
longitudinal position when the front face is placed against the skin of a
surgical patient and a longitudinal force is applied to the actuator
handle.

20. The surgical instrument assembly of claim 11 further comprising
symbols formed on external surfaces of the hollow sheath body and the
handle actuator for indicating operating modes of the surgical instrument
assembly.

21. A method for operating a surgical instrument assembly comprising the
steps of: positioning a hollow sheath body at a first longitudinal
position to encapsulate a surgical instrument inside the hollow sheath
body; locking the hollow sheath body in the first longitudinal position
when the surgical instrument is not being used for surgery; unlocking the
hollow sheath body from the first longitudinal position; positioning the
hollow sheath body to a second longitudinal position to expose the
surgical instrument out from the hollow sheath body by a first desired
length suitable for performing free hand surgery; and, locking the hollow
sheath body in the second longitudinal position when the surgical
instrument is being used for free hand surgery.

22. The method of claim 21 wherein the step of positioning the hollow
sheath body to the first longitudinal position is performed by a
compression spring positioned to apply a bias force that biases the
hollow sheath body to the first longitudinal position.

23. The method of claim 22 further comprising the step of while the
hollow sheath body is locked in the first position, passing a suture
through a notch opening formed through the hollow sheath body adjacent to
the surgical instrument and cutting the suture while the surgical
instrument is encapsulated inside the hollow sheath body.

24. A method for operating a surgical instrument assembly that includes a
surgical instrument, a hollow sheath body and a handle actuator
comprising the steps of: positioning a hollow sheath body to a first
longitudinal position that encapsulates a surgical instrument inside the
hollow sheath body; placing a front face of the hollow sheath body on a
skin surface of a surgical patient while orienting a longitudinal axis of
the surgical instrument substantially normal to the skin surface;
applying a longitudinal force to the handle actuator directed toward the
skin surface to thereby position the hollow sheath body to a third
longitudinal position to expose the surgical instrument out from the
hollow sheath body by a second desired length suitable for making a
dermatotomy in a percutaneous procedure.

25. The method of claim 24 further comprising the step of repositioning
the hollow sheath body to the first longitudinal position after the
surgical instrument is withdrawn from the skin of the patient by applying
a spring bias force that biases the hollow sheath body to the first
longitudinal position.

26. The method of claim 24 further comprising the step of aligning the
surgical instrument assembly with a guide wire exiting from a surgical
patient by engaging the guide wire with a guide wire receiving groove
formed on an external surface of the hollow sheath body.

27. The method of claim 26 comprising the step of positioning an end of
said guide wire receiving groove approximately 0.5 mm away from an
aperture on said front face of said surgical instrument assembly.

28. The method of claim 26 comprising the step of providing a seal around
a dilator inserted around said guide wire exiting from a patient using
said surgical instrument assembly to make said dermatotomy a
predetermined distance from said dilator.

Description:

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a multifunctional scalpel usable
as a traditional cutting scalpel and usable for dermatotomy or "skin
nick" in percutaneous procedures. In particular, the multifunctional
scalpel includes elements for engagement to a guide wire, a scalpel blade
for safety, positioning the scalpel blade for piercing, and positioning
the scalpel blade for conventional cutting.

[0003] 2. Description of the Related Art

[0004] Percutaneous medical procedures use a needle-puncture of the skin
to gain access to an internal location such as a blood vessel, hollow
internal cavity, internal organ or other internal location. In many
applications, percutaneous medical procedures are preferred over "open"
surgery which has more complications. Most percutaneous medical
procedures are a variation of the Seldinger technique which involves
inserting a hollow needle or trocar into a desired internal location and
passing a round-tipped guide wire through the hollow needle until a
leading end of the guide wire exits the trocar at the desired internal
location. The trocar is then removed by advancing it along the guide wire
to its trailing end. While the trocar punctures the skin and installs the
guide wire into a blood vessel or other internal cavity, the initial
puncture surrounding the guide wire usually needs to be enlarged using a
scalpel or other cutting or piercing instrument. After the initial
puncture surrounding the guide wire is enlarged, a hollow "sheath" or
blunt cannula is passed along the guide wire and inserted through the
enlarged puncture wound. The hollow sheath has a larger lumen passing
along its axial length and is guided to the desired internal location by
the guide wire. Once the sheath is in place, the guide wire is removed
and various surgical tools can be installed through the sheath lumen to
the desired location.

[0005] The procedure for enlarging the initial needle puncture surrounding
the guide wire is referred to as a dermatotomy or "skin nick". Ideally,
the dermatotomy is substantially coincident with or immediately adjacent
to the guide wire entry point. In addition, the depth and size of the
dermatotomy may vary for different surgical procedures, different
instrument sheath sizes and different body locations. Heretofore the
dermatotomy was performed by a surgeon using a conventional scalpel
having its cutting blade fully extended and locked in place while held in
a free hand and using only visual guidance to position dermatotomy
coincident with or immediately adjacent to the guide wire entry point and
to make the dermatotomy with a cut depth and length that is suitable for
the situation. Even under ideal circumstances, such as with good lighting
and a well positioned patient, a dermatotomy performed with a
conventional scalpel may not be optimal when it is performed free hand.
Moreover, a dermatotomy may need to be performed under non-ideal
circumstances, e.g. when performed quickly in an emergency, when
preformed in a low light level or when performed with the patient poorly
positioned and such procedures are even more difficult to perform
optically with a free hand held conventional scalpel.

[0006] More recently tools have been developed for guided dermatotomy
procedures. In particular, US 2004/0181246 by Heppler, discloses a
scalpel configured with a pair of wire guides attached to the scalpel and
configured to be guided along the guide wire so that the scalpel blade is
guided to the location where the dermatotomy needs to be placed, e.g.
coincident with or immediately adjacent to the guide wire entry point. As
further disclosed in Heppler, the wire guides can be attached to the
scalpel handle, to the scalpel blade, to a plate sandwiched between the
scalpel handle and the scalpel blade or to a movable safety sheath that
fits over the scalpel blade and partially over the scalpel handle. While
the improved scalpel taught by Heppler is usable for both freehand
cutting and guided dermatotomy procedures, the movable safety sheath
disclosed by Heppler appears difficult to use. Moreover, it is unclear
from the disclosure how the safety shield is attached to the scalpel or
moved from multiple operating positions including a depth stop position.
Accordingly there is a need for an improved scalpel usable for guided
dermatotomy procedures as well as for free hand cutting that provides a
more reliable blade retracting mechanism and blade locking mechanism for
locking the blade in a plurality of different positions and a more robust
mechanism for setting a blade depth stop position for desired cut depths,
such as for consistently performing a dermatotomy with a desired length
and cut depth.

SUMMARY OF THE INVENTION

[0007] The present invention overcomes the problems cited in the prior art
by providing improved surgical instrument assemblies (10, 11) that
support a surgical instrument (20), such as a scalpel blade, in a fixed
position and provide a hollow sheath body (18) that is longitudinally
movable with respect to the surgical instrument 20 to alternately
encapsulate the surgical instrument 20 inside a second cavity (32), in a
safety mode, or expose the surgical instrument through a front face (23),
by a desired dimension, when the surgical instrument is being used for
surgery. In particular, the sheath body 18, 200 is movable to expose
different lengths of the surgical instrument 20 for different
applications and can be locked in various positions as required. In
addition, the surgical instrument assembly is usable to pierce or make an
initial cut in a surgical patient.

[0008] In particular the surgical instruments (10, 11) are operable in a
pierce mode for performing a dermatotomy procedure by placing the front
face (23) of the hollow sheath body (18, 200) against the skin or other
surface of a surgical patient and orienting the longitudinal axis of the
surgical instrument substantially normal to the skin or other surface of
the surgical patient. Next a longitudinal force is applied to the
actuator handle in a direction that pushes the handle toward the skin or
other surface of a surgical patient. The longitudinal force applied to
the handle actuator forces the surgical instrument, in this case a
pointed scalpel blade, through the instrument aperture (22) while
simultaneously forcing the hollow sheath body to be translated
longitudinally toward the handle actuator. The depth of the pierce cut is
controlled by limiting the longitudinal travel distance of the hollow
sheath body to a travel distance associated with a desired cut depth of
the pointed scalpel. This is accomplished by configuring the hollow
sheath body and the handle actuator with an interface suitable for
limiting the travel distance of the hollow sheath body. In one example,
female engaging elements such as a slot arrangement having a plurality of
longitudinal slot is formed on the hollow sheath body and engaged with a
male engaging element formed on the handle actuator with one longitudinal
slot length equal to the desired hollow sheath body travel distance
associated with a desired cut depth of the pierce cut. In addition, the
sheath body (18, 200) includes a guide wire receiving groove (24) formed
on an external surface of the sheath body (18) adjacent to an instrument
aperture (22) formed at the front end of the sheath body. The guide wire
receiving groove (24) receives a guide wire therein and the guide wire is
used to guide the surgical instrument (20), e.g. to guide the scalpel
point (82) to a location defined by the guide wire during a pierce cut.
Accordingly, the surgical instruments (10, 11) are usable to perform a
guided dermatotomy.

[0009] The present invention further overcomes problems of the prior art
by providing methods for operating a surgical instrument assembly. In
particular the methods include positioning a hollow sheath body to a
first longitudinal position for encapsulating the surgical instrument
inside an instrument cavity and locking the hollow sheath body in the
first position when the surgical instrument is not being used for
surgery. The method also includes positioning the hollow sheath body to a
second longitudinal position for causing the surgical instrument to
extend through the instrument aperture with a desired length suitable for
performing free hand surgery and locking the hollow sheath body in the
second position when the surgical instrument is being used for free hand
cutting.

[0010] Further methods include passing a suture through a notch opening
formed through the hollow sheath body adjacent to the surgical instrument
and cutting the suture while the surgical instrument is safely
encapsulated inside the instrument cavity.

[0011] A further method include performing a guided dermatotomy procedure
by first positioning the hollow sheath body in the first longitudinal
position with surgical instrument encapsulated safely inside an
instrument cavity but without locking the hollow sheath body in the first
position. The instrument is then positioned with the front face of the
hollow sheath body on a skin or other surface of a surgical patient while
orienting the instrument longitudinal axis substantially normal to the
skin surface. A user then applies a longitudinal force to the handle
actuator pushing the handle toward the patient skin or other surface.
This causes the surgical instrument to pierce the skin of the surgical
patient to a desire pierce depth while simultaneously forcing the hollow
sheath body toward the handle actuator. The depth of the pierce cut is
controlled by limiting the longitudinal travel of the hollow sheath body.
It is an object of the present invention to provide a scalpel that can be
used for both cutting, in open surgery, and for piercing the skin to a
desired depth, e.g. for a performing guided dermatotomy procedure.

[0012] It is an object of the present invention to provide a scalpel that
includes a guide wire receiving groove aligned with a feature of the
surgical instrument for receiving a guide wire into the receiving groove
and directing the surgical instrument feature to a location defined by
the guide wire.

[0013] It is a further object of the invention to provide a surgical
instrument assembly that includes a sheath body (18, 200) that is movable
to a LOCK position for enclosing the surgical instrument (20) inside the
sheath body (18, 200) to thereby protect the instrument, to protect the
surgical patient, and to protect anyone handling the surgical instrument
assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The features of the present invention will best be understood from
a detailed description of the invention and a preferred embodiment
thereof selected for the purposes of illustration and shown in the
accompanying drawings in which:

[0015] FIG. 1 illustrates a first surgical instrument assembly embodiment
shown in an isometric view according to the present invention.

[0016] FIG. 2 illustrates the first surgical instrument assembly
embodiment shown in section view according to the present invention.

[0017] FIG. 3A illustrates a first surgical instrument holder embodiment
shown in isometric view according to the present invention.

[0018] FIG. 3B illustrates a second surgical instrument holder embodiment
shown in isometric view according to the present invention

[0019]FIG. 4 illustrates a front end of a surgical instrument holder
including a pointed scalpel blade attached thereto shown in isometric
view according to the present invention.

[0020]FIG. 5A illustrates a first arrangement of slotted elements shown
in plan view and usable as a female engaging element according to a
preferred embodiment of the present invention.

[0021]FIG. 5B illustrates the first arrangement of slotted elements
usable as a female engaging element shown on a cylindrical wall according
to the present invention.

[0022] FIG. 6A illustrates a first surgical instrument assembly embodiment
shown in section view with a hollow sheath body shown in a LOCK position
according to the present invention.

[0023] FIG. 6B illustrates the first surgical instrument assembly
embodiment shown in section view with a hollow sheath body shown in a
PIERCE position according to the present invention.

[0024] FIG. 6C illustrates the first surgical instrument assembly
embodiment shown in section view with a hollow sheath body shown in a CUT
position according to the present invention.

[0025] FIG. 7A illustrates a second surgical instrument assembly
embodiment shown in section view with a hollow sheath body shown in a
LOCK position according to the present invention.

[0026] FIG. 7B illustrates the second surgical instrument assembly
embodiment shown in section view with a hollow sheath body shown in a
PIERCE position according to the present invention.

[0027] FIG. 7C illustrates the second surgical instrument assembly
embodiment shown in section view with a hollow sheath body shown in a CUT
position according to the present invention.

[0028] FIG. 8 schematically illustrates markings on outside surfaces of
the handle actuator and the hollow sheath body for indicating
configurations of the surgical instrument.

[0029] FIG. 9A illustrates a second arrangement of slotted elements shown
in plan view and usable as a female engaging element according to the
present invention.

[0030] FIG. 9B illustrates the second arrangement of slotted elements
usable as female engaging elements shown on a cylindrical wall according
to the present invention.

[0031] FIG. 10A illustrates a third arrangement of slotted elements shown
in plan view and usable as a female engaging element according to the
present invention.

[0032] FIG. 10B illustrates the third arrangement of slotted elements
usable as female engaging elements shown on a cylindrical wall according
to the present invention.

[0033] FIG. 11A illustrates a fourth arrangement of slotted elements shown
in plan view and usable as a female engaging element according to the
present invention.

[0034]FIG. 11B illustrates the fourth arrangement of slotted elements
usable as female engaging elements shown on a cylindrical wall according
to the present invention.

[0035] FIG. 12 illustrates a front end view of the surgical assembly
showing a bridge between the instrument aperture and the guide wire
receiving groove.

[0036] FIG. 13A illustrates a hole for insertion of a guide wire, dilator
or catheter, and a pierce cut spaced from the hole by a patient bridge
area having a spacing determined by the surgical instrument assembly
according to the present invention.

[0037] FIG. 13B illustrates an expanded hole of FIG. 13A with a dilator
partially inserted therein causing the patient bridge area to encroach
into the pierce cut opening and still providing a seal against the
dilator.

[0038] FIG. 13C illustrates the expanded hole of FIG. 13B with the dilator
142 fully inserted therein causing the patient bridge area to separate,
and the outer skin of the pierce cut providing a seal against the
dilator.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0039] Referring to FIGS. 1 and 2, FIG. 1 depicts an isometric view of a
surgical instrument assembly 10, according to a first embodiment of the
present invention, and FIG. 2 depicts a section view taken through a
longitudinal axis L of the surgical instrument assembly 10. The surgical
instrument assembly 10 generally has a back end 12 formed by a handle
actuator 14 and a front end 16, opposed to the back end 12, formed by a
hollow sheath body 18. A surgical instrument 20, such as a scalpel blade,
is fixedly attached to an instrument holder 34A with the instrument
holder and scalpel blade 20 supported inside internal hollow cavities of
the handle actuator 14 and hollow sheath body 18.

[0040] Referring now to FIGS. 1-4, the instrument holder 34A comprises a
longitudinal shaft extending along the instrument longitudinal axis L
from the front end 16 to the back end 12. At its front end, the
instrument holder 34A is configured to support the surgical instrument 20
in a desired orientation. At its mid section the instrument holder 34A
includes a longitudinal front shaft portion 62 that guides and supports
longitudinal movement of the hollow sheath body 18. At its back end, the
instrument holder 34A includes a longitudinal back shaft portion 60 that
guides and supports rotation of the handle actuator 14 about the
longitudinal axis L.

[0041] Generally, the surgical instrument assembly 10 is configured such
that the instrument holder 34A and surgical instrument 20 remain
substantially fixedly disposed along the longitudinal axis L. The
surgical instrument assembly 10 is further configured to translate the
hollow sheath body 18 longitudinally toward the back end 12 to expose the
surgical instrument 20. The surgical instrument assembly 10 is further
configured to rotate the handle actuator 14 about the longitudinal axis L
and about the hollow sheath body 18 for locking or unlocking the position
of the hollow sheath body 18 at desired positions. As will be detailed
below, the hollow sheath body 18 includes a front face 23 and an
instrument aperture 22 passing through the front face 23. As the hollow
sheath body 18 is longitudinally translated toward the back end, the
surgical instrument 20 is exposed through an instrument aperture 22.

[0042] The handle actuator 12 includes a pair of diametrically opposed
fins 15 extending radically outward from an outer surface of the actuator
handle 12 to improve the gripping of the handle actuator 14 during use as
a surgical instrument and while rotating the handle actuator 14 to
different operating positions. Of course other gripping aids are usable
on the handle actuator 12 without deviating from the present invention.
Similarly, the hollow sheath body 18 includes a raised diameter 19 to
provide a gripping feature on the hollow sheath body 18 to improve
gripping during use as a surgical instrument and while translating the
hollow sheath body 18 to different operating positions.

[0043] In FIGS. 1 and 2, the surgical instrument 10 is shown in a safety
or LOCK mode wherein the surgical instrument 20 is completely housed
inside the hollow sheath body 18 to protect the surgical instrument 20
from damage and to allow safe storage and handling of the surgical
instrument 10. As detailed below, the hollow sheath body 18 may be
retracted to exposed the surgical instrument 20 through the aperture 22
and the hollow sheath body 18 may be locked or otherwise held in one or
more retracted positions with the surgical instrument 20 exposed for free
hand cutting. Alternately, the hollow sheath body 18 may be unlocked in a
PIERCE mode wherein the front face 23 is placed against the skin of a
surgical patient and the surgical instrument 20 is used to pierce the
skin to a desired depth and cut length by pushing the handle actuator 14
longitudinally toward the skin of the surgical patient.

[0044] According to a further aspect of the present invention, the hollow
sheath body 18 includes a wire receiving groove 24 formed on an external
surface thereof. The wire receiving groove 24 is provided to engage with
a guide wire such as a wire that may be exiting from a blood vessel or
internal cavity of a surgical patient such as during the initial steps of
a percutaneous medical procedure. Generally, the guide wire receiving
groove 24 is formed on an external surface of the hollow sheath body 18
at the front end 12 front end adjacent to the instrument aperture 22 and
the wire receiving groove 24 is aligned with an axis of the surgical
instrument 20, such as a cutting blade point, or the like, for guiding
the axis of the surgical instrument 20 to a desired location such as
toward the initial needle puncture that was used to insert the guide wire
into the surgical patient.

[0045] According to a further aspect of the present invention, the hollow
sheath body 18 includes a notch 17 passing through an outside wall of the
hollow sheath body 18 near the front end 16. In particular, the notch 17
is positioned to provide access to a cutting blade of the surgical
instrument 20 at times when the surgical instrument 20 is completely
encapsulated by the hollow sheath body 18 such as when the hollow sheath
body is in the lock position. Accordingly, the cutting blade of the
surgical instrument 20 can be used to cut a suture, or the like, without
exposing the blade. To cut a suture or the like, the surgical instrument
assembly 10 is positioned to receive the suture through a top opening of
the notch 17 and tension between the suture and the blade is used to cut
the suture at a desired position without exposing the surgical instrument
20. This is a very important safety feature in an operating room
environment. The notch 17 has a top opening sized and shaped large enough
to allow a suture material to enter the notch 17 and be cut by the blade,
but the top opening is formed to prevent the blade from cutting anything
that will not fit through the top opening. Accordingly the notch 17 is
formed with a top opening dimension of approximately 3 mm or less and
preferably about 1 mm.

[0046] Referring to FIGS. 1 and 2 the handle actuator 14 comprises an
annular body disposed along the longitudinal axis L and encloses a first
internal longitudinal cavity 26 extending along the longitudinal axis L
and sized to receive a back portion of the hollow sheath body 18 therein.
The first internal longitudinal cavity 26 is closed at its back end by an
end wall 28 and forms a first aperture 30 at the first longitudinal
cavity front end.

[0047] The hollow sheath body 18 comprises an annular body disposed along
the longitudinal axis L and encloses a second internal longitudinal
cavity 32, extending along the longitudinal axis L and sized to receive
the surgical instrument holder 34A, shown in FIG. 3A, or an alternate
embodiment of the surgical instrument holder 34B, shown in FIG. 3B,
therein. The second longitudinal cavity 32 forms a second aperture 36 at
the second longitudinal cavity back end and the second longitudinal
cavity 32 is shaped at the front end as may be required to enclose the
surgical instrument 20 and to provide a suitable instrument aperture 22
that allows the surgical instrument 20 to pass through a front wall 23.

[0048] Turning now to FIGS. 2, 3A, 3B, 4, and the section views of FIGS.
6A-7C, two different embodiments of surgical instrument holders 34A and
34B are shown in isometric view in FIGS. 3A and 3B respectively. The
instrument holder 34A installs in the surgical instrument assembly 10, as
shown in the section views of FIGS. 2 and 5A-6C. The instrument holder
34B installs in a second embodiment of a surgical instrument assembly 11,
shown in the section the views of FIGS. 7A-7C.

[0049] Referring to both FIGS. 3A and 3B the instrument holders 34A and
34B include a pointed scalpel blade 68 attached to front ends thereof.
The holders 34A and 34B each comprise a solid substantially uniform
diameter elongated front shaft portion 62 disposed along the surgical
instrument longitudinal axis L and extending between an instrument
holding portion 70 and an increased diameter back shaft portion 60. The
back shaft portion 60 has a larger diameter than the front shaft portion
62 and includes features on the back end thereof for interfacing with the
handle actuator 14. In particular, the back shaft portion 60 includes a
back end formed with an annular groove 66 having a decreased groove
diameter axially centered with respect to the longitudinal axis L for
interfacing with the handle actuator 14. In addition, a shoulder is
formed at the intersection of the back shaft portion 60 and the front
shaft portion 62 and the shoulder provides an annular land surface 64. As
depicted in FIG. 3A, the first instrument holder 34A has a long front
shaft 62 with the annular land surface 64 positioned adjacent to the
annular groove 66 near the back end of the instrument holder 34A. As
depicted in FIG. 3B, the second instrument holder 34B has a shorter front
shaft 62 with the annular land surface 64 approximately positioned at the
mid point of the holder 34B.

[0050] Referring now to FIG. 4, the instrument holders 34A and 34B each
include an instrument holding portion 70, which may be formed integral
with the front shaft portion 62, or which may comprise a separate element
fixed or removable from the front shaft portion 62. Generally, the
instrument holding portion 70 provides features usable to attach a
surgical instrument, e.g. the scalpel 68, to the instrument holder 34A or
34B and for orienting the scalpel 68 in a desired orientation and or
location with respect to the longitudinal axis L.

[0051] In the particular example where the surgical instrument is a
conventional scalpel blade 68 formed with a pointed tip 82, the
instrument holding end 70 is formed with a flat surface 72 for receiving
a shank 80 of the scalpel blade 68, thereon. The flat surface 72 also
includes a pair of attaching posts 74 and 76 attached thereto and
extending substantially perpendicular from the flat surface 72 to engage
with a slotted opening 78. The slotted opening 78 is sized to mate with
the attaching posts 74 and 76 and the attaching posts 74 and 76 are
positioned and oriented to align an axis of the scalpel blade 68 with the
instrument longitudinal axis L. Specifically, the scalpel 68 is oriented
coplanar with the longitudinal axis L and the blade point 82 is offset
from the longitudinal axis L by a desired offset distance C. In addition,
the fit of the slotted opening 78 with the attaching posts 74 and 76 may
be an interference or snap fit to mechanically clamp the blade shank 80
in position. Alternately, other clamping or attaching elements may be
employed.

[0052] According to a preferred embodiment of the present invention, the
surgical instrument assemblies 10 and 11 are configured with the scalpel
blade 68. However, other scalpel blade types including a rounded scalpel
blade, a micro-blade scalpel are usable without deviating from the
present invention. Moreover other surgical instruments such as other
cutting tools, solid or hollow needles, probes directors, tweezers or
forceps, dilators, expanders or retractors are usable without deviating
from the present invention. Moreover other medical devices such as
electronic or optical instruments, drug delivery devices or the like,
that may need to be guided along a guide wire to a wire puncture may be
usable in combination with the features and elements of the present
invention described herein.

[0053] Referring to FIGS. 2, 3A and 6A-6C the surgical instrument holder
34A and the attached surgical instrument 20 installs into the hollow
sheath body 18 second longitudinal cavity 32 through the second aperture
36. In the example of FIGS. 6A-6C, the second longitudinal cavity 32 has
a substantially uniform diameter 42 over its full length for receiving
the instrument holder front shaft diameter 62 therein. Alternately, a
front portion of the second longitudinal cavity 32 may be shaped as
required to receive larger surgical instruments 20 therein. An annular
land surface 45 is formed by the back end of the sheath body 18 and is
used as a bearing surface for a compression spring 53. The compression
spring 53 is a cylindrical spring element open along its longitudinal
axis and the spring 53 installs over the instrument holder front end
diameter 62 and is captured between the annular land surface 45, formed
on the back end of the sheath body 18, and the annular land surface 64
formed on the instrument holder 34A adjacent to the annular groove 46.
The compression spring 53 delivers a longitudinal separating force
between the instrument holder 34A, which is longitudinally fixed in
place, and the sheath body 18, which is longitudinally movable and the
spring 53 tends to bias the longitudinal position of the sheath body 18
toward the instrument front end 16.

[0054] Referring to FIGS. 3B and 7A-7C, the second embodiment of the
surgical instrument assembly 11 includes a second embodiment of a hollow
sheath body 200 formed with an internal cavity 202 formed therein. In
this embodiment, the surgical instrument holder 34B and surgical
instrument 20 install into the longitudinal cavity 202 through the
aperture 204. The internal cavity 202 has a substantially uniform front
diameter 206, sized to receive the instrument holder front diameter 62
therein, and the second longitudinal cavity 202 has a larger back
diameter 208 sized to receive instrument holder back shaft portion 60
therein. A shoulder separating the front diameter 206 and back diameter
208 forms an annular land surface 210 which is used as a bearing surface
for a compression spring 52. The compression spring 52 is a cylindrical
spring element open along its longitudinal axis and the spring 52
installs over the instrument holder front diameter 62 and is captured
between the annular land surface 210 and the annular land surface 64
formed on the instrument holder 34B. The compression spring 52 delivers a
longitudinal separating force between the instrument holder 34B, which is
longitudinally fixed in place, and the sheath body 200 which is
longitudinally movable, and the spring 52 tends to bias the sheath body
200 toward the instrument front end 16.

[0055] In each of the example instrument assemblies 10 and 11, internal
surfaces of the sheath body 18 and 200, and external surfaces of the
instrument holder 34A, 34B as well as internal surfaces of the actuator
handle 14 and external surfaces of the hollow sheath body 18 and 200 are
fit together with a clearance fit that allows longitudinal translation of
the sheath body 18, 200 with respect to the instrument holders 34A or 34B
and the actuator handle 18 as well as rotation of the actuator handle 18
about the longitudinal axis L and about hollow sheath body 18 and the
clearance fits are made sufficiently small that the surgical instrument
20, instrument holder 34A, 34B sheath body 18, 200 and actuator handle 14
are maintained in substantial alignment with the instrument longitudinal
axis L. Specifically, the diametrical clearance between mating elements
may range from about 0.25-1.25 mm.

[0056] Referring to FIGS. 1, 2, and 6A-7C the back end of the surgical
instrument holders 34A and 34B and the back end of the sheath body 18 or
200 install into the handle actuator first longitudinal cavity 26 by
passing through the actuator handle front end aperture 30. The actuator
handle 14 includes an annular lip 46 formed substantially opposed to the
end wall 28. The annular lip 46 reduces the diameter of the first
longitudinal cavity 26 and is axially centered with respect to
longitudinal axis L. The annular lip 46 is provided to engage with the
instrument holder annular groove 66 by pressing or otherwise placing the
back end of the instrument holder back shaft 60 into engagement with the
annular lip 46. Alternately the handle actuator 14 may be configured with
two longitudinal half sections that engaged with the annular groove 66 at
assembly and that may be bonded or otherwise fastened together at
assemble. The engagement of the annular lip 46 with the annular groove 66
prevents longitudinal movement of the instrument holder 34A or 34B and
the handle actuator 14. The annular lip 46 and annular groove 66 are each
sized to fit together with a clearance fit. The clearance fit is made
sufficiently large that the actuator handle 14 can be rotated about the
longitudinal axis L with respect to the instrument holder 34A or 34B.
Meanwhile, the clearance fit between the annular lip 46 and annular
groove 66 is small enough to maintain the instrument holder back shaft 66
in substantial alignment with the instrument longitudinal axis L. For
example, the diametrical and axial clearances between the annular lip 46
and annular groove 66 may range from about 0.25-1.25 mm. Alternately, a
snap ring or other suitable fastener may be used instead of the annular
lip 46 and installed through an annular groove formed through the handle
actuator 14.

[0057] Referring now to FIGS. 2, and 5A-6C, the handle actuator 14
includes a fixed pin 48 or other male engaging element protruding
substantially axially inward from an inner wall of the first longitudinal
cavity 26. The pin 48 may be integrally formed with the handle actuator
14, such as molded in place, or the pin 48 may comprise a set screw, or
the like, threaded through a wall of the first longitudinal cavity 26.
The sheath body 18, 200 includes a female engaging element 50, such as an
arrangement of slotted elements described below for receiving the male
engaging element 48 therein. Specifically, the female engaging element 50
passes fully or partially through an outer wall of the sheath body 18 and
is sized to movably receive the fixed pin 48 therein with a minimum of
clearance between the pin and female engaging element 50. The
longitudinal position of the pin 48 is fixed with respect to the actuator
handle end wall 28 such that rotation of the actuator handle 14 rotates
the pin 48 in a circular path around the longitudinal axis L at a fixed
longitudinal position. By engaging with the slot 50, the rotation of the
actuator handle 18 and therefore the pin 48 about the longitudinal axis L
may be used engage the pin 48 with various features of the female
engaging element 50, such as detents and longitudinal slot sections, in
order to select a desired longitudinal position of the sheath body 18,
200. Accordingly, the female engaging element 50 may be formed with
various longitudinal slots, and with detents which when engaged with the
pin 48 allow longitudinal translation of the hollow sheath body 18, 200
and may hold the sheath body in desired longitudinal positions. In
addition, the pin 48 may be supported on a flexure extending between the
pin 48 and the handle actuator 14 for allowing the pin 48 to flex axially
away from the longitudinal axis L during assembly of the instrument.
Alternately, the entire actuator handle 14 may be constructed as a
flexure with flexible elements formed integral with the actuator handle
to flexibly expand its inside diameter during assembly to allow the pin
48 to pass over the hollow sheath body 18, 200 before engaging with the
female engaging element 50.

[0058] According to the invention, the surgical instrument assembly 10 and
11 are assembled by installing the spring 52 or 53 onto the instrument
holder front shaft 62, installing the surgical instrument 20 onto the
instrument holding portion 70 and then installing the surgical instrument
holder 34A, 34B into the sheath body second longitudinal cavity 32, 202
through the sheath body second aperture 36, 204. The back end of the
surgical instrument holder 34A, 34B and the back end of the sheath body
18, 200 are then installed into the actuator handle first longitudinal
cavity 26 through the handle actuator first aperture 30 and pushed
longitudinally from the front end 16 to engage the instrument holder
annular groove 66 with the handle actuator annular lip 46. The handle
actuator 14 is then rotated about the longitudinal axis L until the male
engaging element or fixed pin 48 is engaged with the female engaging
elements or arrangement of slotted elements 50.

[0059] Referring now to FIGS. 5A and 5B, a preferred embodiment of a
female engaging slot arrangement 90 is shown in plan view in FIG. 5A and
shown in FIG. 5B disposed on a hollow cylindrical element 92. The element
92 corresponds with a cylindrical mid section of the hollow sheath body
18 or 200. The female engaging slot arrangement 90 may comprise slotted
openings passing completely through the thickness of an outer annular
wall of the cylindrical element 92 or the slotted openings may have a
slot depth that is less than the wall thickness of the cylindrical
element 92 but deep enough to engage with the male engaging element 48.
The surgical instrument longitudinal axis L is shown coincident with the
longitudinal axis of the hollow cylindrical element 92 and the
cylindrical element front end and back end correspond with the surgical
instrument front end 16 and back end 12 as described above.

[0060] According to a preferred embodiment of the present invention, the
male engaging pin 48 engages with the female engaging slot arrangement 90
while the hollow sheath body 18, 200 is continuously biased toward the
front end 16 by the compression springs 52, 53. In the LOCK position, the
hollow sheath body 18, 200 is at its front most position where it
encapsulates the surgical instrument 20. In the Lock position, the male
engaging pin 48 is engaged with a back detent slot 94. To unlock the
surgical instrument assembly, a user grasps the hollow sheath body
gripping region 19 and the handle actuator 14 and pulls the sheath body
18, 200 toward the instrument back end 18 until the pin 48 is engaged
with the cross slot section 96. Thereafter the handle actuator 14 can be
rotated clockwise, as viewed from the back end 18, to engage with a cut
slot 98. Alternately, the handle actuator 14 may be rotated
counter-clockwise to engage with a pierce slot 100.

[0061] If engaged with the cut slot 98, the user pulls the sheath body 18,
200 further toward the instrument back end 18, and then further rotates
the handle actuator 14 clockwise to engage the pin 48 with a cut detent
slot 102. Once engaged in the cut detent slot 102, the spring bias force
pushes the hollow sheath body forward against the male engaging pin 48
thereby locking the hollow sheath body 18, 200 in a CUT position. The cut
position is shown in FIGS. 6C and 7C which show the surgical instrument
20 extending out from the instrument aperture by a distance E.

[0062] If rotated to the pierce slot 100, the bias force pushes the hollow
sheath body forward to engage the male engaging pin 48 with a pierce
detent 104 and hold it in place therein. The pierce detent 104 is
co-aligned with the pierce slot 100. The pierce detent 104 is configured
to position the sheath body substantially in its forward most position
which encapsulates the surgical instrument 20. To use the surgical
instrument in the PIERCE mod, the user places the instrument front face
23 against the skin of a surgical patient with the instrument
longitudinal axis L substantially normal to the skin surface. The user
may also use the wire receiving groove 24 with a guide wire exiting from
the surgical patient to position the front face 23 for making a piece cut
adjacent to the where the guide wire exits a blood vessel or internal
cavity of the surgical patient. The user then pushes the handle actuator
14 substantially longitudinally thereby driving the instrument holder and
surgical instrument toward the skin of the surgical patient where the
surgical instrument 20 pierces the skin proximate to the guide wire. In
response to the user pushing the handle actuator 14 substantially
longitudinally, the hollow sheath body 18 remains stationary while the
male engaging pin 48 moves along the length of the pierce slot 100.
Accordingly, the depth of the piercing cut is controlled by the length of
the pierce slot 100 which stops the travel of the handle actuator and
surgical instrument holder when the male engaging pin 48 impacts the
front end of the piercing slot 100.

[0063] After completing a piercing cut, the bias force of the compression
spring 52, 53 acts to separate the handle actuator 14 and sheath body 18,
200 thereby retracting the surgical instrument 20 from the surgical
patient until the male engaging pin 48 is once again in the pierce detent
104 and the handle actuator, surgical instrument holder 34A or 34B and
the surgical instrument 20 have moved to a position where the surgical
instrument is again encapsulated inside the hollow sheath body 18, 200.
In the PIERCE mod, the surgical instrument 20 moves to extend out from
the front face 23 by a distance D shown in FIGS. 6B and 7B. The distance
D is controlled by the length and position of the pierce slot 100.

[0064] Referring now to FIG. 8, example markings or other indicia usable
on outside surfaces of the surgical instrument 10, 11 are shown
schematically. An single arrow head 120 is shown on an outside surface
near a front edge of the handle actuator 14 centered on the longitudinal
axis L. The arrow head 120 points toward a lock symbol 122 shown on an
external surface of the hollow sheath body 18, 200 and adjacent to an
edge of the handle actuator 14. The arrow 120 and lock symbol 122 are
positioned such that with the arrow head 120 pointing toward the lock
symbol 122, the handle actuator 14 and hollow sheath body 18, 200 are
positioned in the LOCK position.

[0065] Two additional symbols are shown on the outside surface of the
hollow sheath body to the left and right of the lock symbol 122. The
symbol 124 is a pierce symbol and the symbol 126 is a cut symbol. When
the handle actuator 14 is rotated to align the male engaging pin 48 with
the pierce 100 or pierce engaging slot 104 the arrow head 120 points
toward the pierce symbol 124. When the handle actuator 14 is rotated to
align the male actuator pin 48 with the cut slot 98 or the cut detent
102, the arrow head 120 points toward the cut symbol 126. Any of the
symbols 120-126 may be marked or decaled onto outside surface of the
handle actuator or the hollow sheath body or the symbols 120-126 may be
formed as surface features such as raised or recessed surfaces.

[0066] Referring now to FIGS. 9A-11B, three different configurations of
female engaging slot arrangements 300, 310, 322 are shown in a plan view
in FIGS. 9A, 10A and 11A. The female slot arrangements 300, 310 and 322
are also shown disposed on a hollow cylindrical element 93 in FIGS. 9B,
10B and 11B. These alternative slot embodiments are shown to illustrate
additional methods and configurations for longitudinally translating the
hollow sheath body 18, 200 to alternately expose the surgical element 20
through the instrument aperture 22 or to encapsulate the surgical element
20 inside the hollow sheath body 18, 200 according to further aspects of
the present invention.

[0067] In the longitudinal slot arrangement 300, shown in FIGS. 9A and 9B
the slot arrangement 300 includes a longitudinal slot 302 and three
detents 304, 306 and 308. A lock detent 302 corresponds to the LOCK
position such that when the male engaging pin 48 is engaged with the lock
detent 302 the hollow sheath body 18, 200 is positioned to encapsulate
the surgical instrument 20 and held in place. A cut detent 308
corresponds the CUT position such that when the male engaging pin 48 is
engaged with the cut detent 308 the hollow sheath body 18, 200 is
positioned to expose the surgical instrument 20 by the distance E from
the front face 23 as shown in FIGS. 6C and 7C and held in place. In
addition, an intermediate detent 306 is provided such that when the male
engaging pin 48 is engaged with the intermediate detent 306 the hollow
sheath body 18, 200 is positioned to expose the surgical instrument 20 by
less than the distance E from the front face 23, such as a distance D
shown in FIGS. 6B and 7B and held in place.

[0068] In the slot arrangement 310, shown in FIG. 10A a longitudinal slot
312 includes a lock detent 314 at its back end and a cut detent 316 at it
front end. The longitudinal slot 312 is used to move the hollow sheath
body 18, 200 between the LOCK position, shown in FIGS. 6A and 7A, and the
CUT position, shown in FIGS. 6C and 7C. A cross slot section 318 allows
the male engaging pin 48 to engage with a pierce slot 320 when the handle
actuator 14 is rotated. With the male engagement pin 48 engaged with a
back end of the pierce slot 320 the hollow sheath body 18 is position to
encapsulate the surgical instrument 20 and the hollow sheath body is
movable to allow the surgical instrument assembly to operate in the
PIERCE mod as described above.

[0069] In the slot arrangement 322, shown in FIGS. 11A and 11B, includes a
spiral slot 321, a lock detent 324, a cut detent 326 and a middle detent
328. With the male engaging pin 48 engaged with the lock detent 324 the
surgical instrument 20 is encapsulated by the hollow sheath body 18,
which is held in place. With the male engaging pin 48 engaged with the
cut detent 326, the surgical instrument extends out from the sheath body
by a distance E as shown in FIGS. 6C and 7C, and the sheath body is held
in place. With the male engaging pin 48 engaged with the middle detent
328 the surgical instrument extends out from the sheath body by less than
the distance E, such as a distance D shown in FIGS. 6B and 7B, and the
sheath body is held in place.

[0070] Referring to FIG. 12, the front end 16 of the surgical instrument
assembly 10 is shown comprising the front face 23, the instrument
aperture 22, a groove 24 for receiving a guide wire, and a bridge 13
which is the distance between the right edge of the instrument aperture
22 and the tip of the groove 24 facing the aperture 22. As previously
discussed, the groove 24 receives a guide wire that may be exiting from a
blood vessel or internal cavity of a surgical patient.

[0071] Referring to FIG. 12 and FIG. 13A, FIG. 13A illustrates a hole or
puncture 132 in a patient 130 for insertion of the guide wire, a dilator
or a catheter, and a pierce cut 136 is spaced from the hole 132 by the
bridge 13. The surgical instrument assembly 10 is positioned normal or
perpendicular to the surface of the surgical patient adjacent to the
existing guide wire extending from the hole or puncture 132 on the
surgical patient 130 so that the front face 23 rests on the surface of
the surgical patient. The groove 24 receives the guide wire and the
pierce mode of the surgical instrument assembly 10 is activated,
resulting in a cut 136 approximately 0.5 mm from the edge of the puncture
or hole 132 from where the guide wire is exiting. The resulting space
between the inner edge of the cut 136 facing the hole 132 and the edge of
the hole 132 is referred to as the patient bridge area 134 which plays an
important role in preventing infections in the patient 130. The cut 136
relieves pressure on the patient's skin 130 and provides for expansion of
the skin of the patient 130 in the patient bridge area 134 when the
dilator is inserted in the hole 132 so the skin does not tear and emit
fluids.

[0072] Referring to FIG. 13B, FIG. 13B illustrates the hole of FIG. 13A
expanded with a dilator 142 partially inserted therein causing the
patient bridge area 134 to expand due to its elasticity into the area of
the pierce cut 136. The surface of the patient bridge area 134 against
the dilator acts as a sling and continues to provide a seal to prevent
fluids from escaping from the hole 132.

[0073] Referring to FIG. 13C, FIG. 13C illustrates the hole 132 of FIG.
13B with the dilator 142 further inserted therein causing the patient
bridge area 134 to widen and separate into portions 134a and 134b.
However, the outer skin edge 140 of the pierce cut 136 continues to form
a seal around the dilator 142. Therefore, the use of the surgical
instrument assembly 10 to provide the accurate pierce cut 136 produces
the approximate 0.5 mm bridge between the hole 132 and the pierce cut 136
which cooperates in providing a seal around the dilator or catheter
without leaving any open area where bleeding or infection could occur.

[0074] It will also be recognized by those skilled in the art that, while
the invention has been described above in terms of preferred embodiments,
it is not limited thereto. Various features and aspects of the above
described invention may be used individually or jointly. Further,
although the invention has been described in the context of its
implementation in a particular environment, and for particular
applications, e.g. as a surgical instrument assembly, those skilled in
the art will recognize that its usefulness is not limited thereto and
that the present invention can be beneficially utilized in any number of
environments and implementations where it is desirable to enclose an
instrument inside a sheath and to guide the instrument to a desired
location during use. Accordingly, the claims set forth below should be
construed in view of the full breadth and spirit of the invention as
disclosed herein.

Patent applications by Rudolph Muto, Andover, MA US

Patent applications by Thomas M. Prezkop, Andover, MA US

Patent applications in class Cutter carried on elongated probe-like member

Patent applications in all subclasses Cutter carried on elongated probe-like member